Automatic fire extinguishing system

ABSTRACT

WATER FLOW UNDER PRESSURE THROUGH A DISTRIBUTION TUBE IN A GIVEN AXIAL DIRECTION IS DISCHARGED AS A MIST INTO THE ATMOSPHERE THROUGH RELATIVELY SMALL BORES IN THE WALL OF THE TUBE WITH THE BORES DIRECTED CONTRARY DIRECTION AT AN ANGLE OF 6* TO 14* FROM THE AXIS OF THE TUBE. A THEMOSTAT TO DETECT A FIRE CONTROLS THE SUPPLY OF PRESSURIZED WATER TO THE DISTRIBUTION TUBE.

Sept. 20, 1971 WHEAR 3,606,166

AUTOMATIC FIRE EXTINGUISHING SYSTEM Original Filed July 21. 1967 4: F860L Wb'fAZ INVENTOR ArrazA/ar Umted States Patent 3,606,166 Patented Sept.20, 1971 3,606,166 AUTOMATIC FIRE EXTINGUISHING SYSTEM Alfred L. Whear,P.O. Box 366, Minden, Nev. 89423 Original application July 21, 1967,Ser. No. 655,152, now

Patent No. 3,512,363, dated May 19, 1970. Divided and this applicationMar. 30, 1970, Ser. No. 23,847

Int. Cl. A62c 35/32 US. Cl. 239--272 2 Claims ABSTRACT OF THE DISCLOSUREWater flow under pressure through a distribution tube in a given axialdirection is discharged as a mist into the atmosphere through relativelysmall bores in the wall of the tube with the bores directed contrary tothe axial direc tion at an angle of 6 to 14 from the axis of the tube. Athermostat to detect a fire controls the supply of pressurized water tothe distribution tube.

CROSS REFERENCES TO RELATED APPLICATIONS This application is a divisionof a co-pending application Ser. No. 655,152, filed July 21, 1967 nowPat. No. 3,512,363 and entitled Moisture Distribution System.

BACKGROUND OF THE INVENTION Conventional fire prevention water sprinklersystems employing metal pipe with conventional sprinkler heads arerelatively expensive and, moreover, conventional sprinkler heads do notdistribute the moisture with high efficiency. The need exists for amoisture distribution system that employs inexpensive conduits and thatdischarges the water into the atmosphere in a fine mist in the manner ofan atomizer.

SUMMARY OF THE INVENTION A basic discovery underlying the invention isthat a relatively long tube having numerous longitudinally spaced outletbores in its wall will meet the requirement for atomized discharge ofwater into the atmosphere, provided that the outlet bores are inclinedupstream at an angle of 6 to 14 relative to the axis of the tube andfurther provided that the tube wall is sufliciently thick to make thebores long enough for directional effect, i.e., to cause the dischargeat each bore to be in a general direction opposite to the direction offlow through the tube.

In a fire prevention sprinkler system or in a system for humidifying theatmosphere for any purpose, water is supplied to the distribution tubesat a substantial pressure, say at a pressure of 25 to 150 p.s.i. and thewater is atomized or reduced to finely divided form as it issues fromeach outlet bore.

In such a high pressure atomizing system, balanced distribution isdesirable in the sense of uniform rates of flow among the numerousreversely directed outlets and substantially simultaneous initiation andcessation of flow at all of the outlets. In practice, such balanced flowrequires that when operation of the system is initiated, the main supplypipe downstream from the master valve fill substantially to capacitybefore water is delivered to any of the manifolds that branch from thesupply pipe and it is further required that each manifold fill tocapacity before any substantial amount of water is discharged into anyof the numerous distribution tubes that branch from the manifold.Finally, each distribution tube should fill to capacity before water isdischarged from any of the distribution outlet bores. Thus, in theoperation of such a balanced system there is an initial delay for thesupply pipe to fill and then a further delay for the manifolds to fillbefore flow is started in the various distribution tubes. Thereafter,the discharge from the reversely directed outlets of the distributiontubes is substantially uniform along the length of each tube.

The desired initial delay in flow from a main supply pipe into itsbranching manifolds is accomplished by providing each manifold with aspecial inlet fitting that projects into the interior of the supplypipe. Each of these inlet fittings has an inlet opening which facesdownstream of the main supply pipe.

In such an arrangement initial flow past each inlet fitting occurs atrelatively high velocity and causes lowering of pressure, i.e., createsa suction effect at the inlet fitting which effect discourages outflowthrough the inlet fitting to the corresponding manifold. The reversepres sure differential or suction effect which discourages out flowthrough the various inlet fittings is only temporary because when thesupply pipe becomes filled substantially to capacity, the flow velocityin the supply pipe drops to terminate the reverse pressure differentialor suction effect and thereby permit flow to start in all of themanifolds substantially simultaneously.

To control the flow from each manifold into the numerous distributiontubes that branch therefrom, each of the distribution tubes is providedwith the same type of inlet fitting, the inlet fitting projecting intothe interior of the manifold and having an inlet opening facingdownstream of the manifold. Here again, the various inlet fittingsresist outflow therethrough until the manifold is filled substantiallyto capacity whereupon outflow is initiated nearly simultaneously throughthe various distribution tubes.

In a high pressure atomizing system the phenomenon of equalized outletflow along the length of a distribution tube is complex and apparentlyis the result of conflicting factors. One factor, of course, is that inany conduit having numerous outlets spaced along its length the pressureprogressively drops along its length, and if pressure alone were theonly factor more water would be released from the outlets at theupstream end of the conduit than at the downstream end. An opposingfactor, however, in a high pressure atomizing system is that each of thereversely directed outlet bores of a distribution tube tends to set up aflow-resisting reverse pressure differential or suction effect. Sincethe tendency to create a reverse pressure differential or suction effectvaries with the velocity of flow through the tube and since the velocityprogressively lowers along the length of the tube, both the flowpromoting effect and the flow resisting effect drop progressively alongthe length of the tube and apparently the difference between the twoeffects is substantially constant along the length of the tube to resultin the desired uniform rate of outflow.

Apparently, additional factors also oppose the flow promoting effect ofthe water pressure at the outlet bores of a distribution tube in a highpressure system. One of these additional factors is that since theoutlet bores of the distribution tube are inclined upstream, thedirection of outflow is locally reversed and the momentum of the flowingwater in the tube makes it difficult for the change in direction tooccur. This conflict inherent in the change of direction of flow createsrelatively violent turbulence at the inlet end of each of the outlets.Another additional factor is that turbulence is further promoted by theimpingement of the stream in the tube against the inclined shouldersthat are formed by the various reversely directed outlet bores. It isthese opposing factors that account for the atomized discharge from thereversely directed outlets of a distribution tube in a high pressuresystem. Thus, the invention teaches a new means for atomized dischargeof water.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view of amoisture distribution system wherein a plurality of spaced distributiontubes branch from a common manifold, the view representing a highpressure atomization system;

FIG. 2 is an enlarged cross section of the manifold taken along the line2-2 of FIG. 1 showing various inlet fittings projecting from thedistribution tubes into the interior of the manifold;

FIG. 3 is a fragmentary longitudinal section along the line 33 of FIG. 2showing one of the inlet fittings;

FIG. 4 is a section along the line 44 of FIG. 2 showing how each of theinlet fittings may be provided With-an exterior flange that indicatesthe orientation of the fitting and also indicates the direction of flowthrough the manifold; and

FIG. 5 is a greatly enlarged longitudinal sectional view of adistribution tube showing the reversely directed bores that constitutethe outlets of the distribution tube.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1-5 show the essentialstructure of a moisture distribution system that may be supplied withwater under high pressure for discharge of the water in the form of amist.

FIG. 1 shows a single manifold with numerous lateral distribution tubes12. The manifold 10 may be made of a suitable plastic such aspolyvinylchloride and the distribution tubes may be made of a suitableplastic such as a polyethylene. The manifold 10 is supplied with waterfrom a pressurized source by a master valve 14 which may have a suitablecontrol 15. The rate at which the water enters the manifold 10 may bevaried by manual adjustment of a choke valve 16 but the choke valve maybe omitted if the master valve 14 incorporates an adjustment for thispurpose.

The control may take various forms in various systems. For example, thecontrol 15 may be simply a handle for manual operation of the mastervalve or may be a push button for electrical actuation of the mastervalve by remote control. For a fire prevention system, the control 15may be a thermally responsive means such as a thermostat or a controlutilizing a low melting material in a well known manner. For ahumidifying system the control 15 may incorporate a suitable humiditydetector.

The simplified system shown in FIG. 1 has a single manifold 10 withprovision for balanced flow to the various branching distribution tubes12. In a more elaborate system having a number of manifolds 10 branchingfrom a common supply pipe, provision would be made for balanced flow tothe various manifolds as will be explained hereafter. The distributiontubes 12 are spaced apart in accord with the particular purpose of thesystem and while the distribution tubes are shown as parallel they arenot necessarily parallel.

Each distribution tube 12 has numerous outlets 18 which, as shown inFIG. 5, are bores in the wall of the tube with each bore inclinedupstream towards its outer end at an angle to the axis of the tubewithin the range of 6 to 14. An angle of approximately 10 i preferred.It will be noted in FIG. 5 that each inclined outlet bore forms asloping shoulder 20 inside the distribution tube which shoulder isexposed to the flowing stream of water.

The outlet bores 18 may be at any desired spacing along the length ofthe distribution tube, for example, a spacing of six inches, suchspacing for any given installation being within the skill expected inthe art. If desired, groups of the outlet bores may be spaced apart sixinches longitudinally of the tube with the bores in each group spacedapart circumferentially of the tube.

The inside diameter of a distribution tube 12 will vary with the lengthof the tube. For example, a distribution tube 50 feet long may have aninside diameter of V16 inch with a wall thickness of /32 inch and thediameter of the outlet bores may be .021 inch. With the tube wall of thestated thickness and with an outlet bore of the specified diameter andwith the outlet bore inclined approximately 10", the length of theoutlet bore will be several times its thickness so that the outlet borewill have a definite directional effect. The directional effect isimportant because it is contemplated that liquid may escape through anoutlet bore only by reversing its direction with respect to thedirection of main flow through the tube.

To achieve balanced initiation of flow among the various distributiontubes 12, each distribution tube is provided with an inlet fitting 22which may be made of a suitable plastic. As shown in FIGS. 2 and 3, eachinlet fitting 22 is of tubular configuration and may be cemented into acorresponding radial bore in the tube wall. In the construction shown,each inlet fitting 22. is provided with a radial flange 24 which abutsthe outer surface of the tube and serves as a stop to determine theextent to which the fitting protrudes into the interior of the manifold10. Each of the tubular inlet fittings 22 is cut off at an acute angleas indicated in FIG. 3 to provide an elliptical inlet opening 25 as maybe seen in FIG. 2 and the inlet fitting is so oriented that theelliptical inlet opening faces downstream.

A feature of the invention is that the radial flange 24 of an inletfitting 2 2 not only serves as a stop when the inlet fitting is beinginstalled in a manifold 10, but also serves as means toindicate theorientation of the inlet fitting. For this purpose the radial flange 24is formed with a point 26 as shown in FIG. 4, the point indicating thedirection in which the inlet opening faces. The pointed flange not onlyprovides guidance for orientation of an inlet fitting in a manifold 10,but also provides guidance in the orientation of a manifold in a system.

As heretofore noted, it is preferred that a manifold 10 be at leastnearly empty when the system is not in operation. With a manifold nearlyempty, initial flow through the manifold is relatively rapid but thepressure in the manifold does not rise until the manifold is filled toits normal capacity. It is this preliminary delay period that providesbalanced starting flow in the sense that overflow starts through all ofthe distribution tubes substantially simultaneously.

It is apparent that the plastic tubing is relatively inexpensive and itis further apparent that, if desired, the tubing may be made ofrelatively flexible plastic.

My description in specific detail of the presently preferred practicesof the invention will suggest various substitutions, changes and otherdepartures from my disclosure within the spirit and scope of theappended claims.

What is claimed is:

1. In a system for distributing liquid in finely divided form into theatmosphere at spaced points in a given region, the combination of:

means to supply the liquid under pressure including a manifold;

a plurality of conduits branching from said manifold at spaced pointsalong its length and extending into the given region for flowtherethrough in a given longitudinal direction;

an inlet fitting for each conduit projecting into the interior of saidmanifold, the inlet fittings having inlet openings facing downstreamwith respect to said given longitudinal direction whereby reduction ofpressure at the inlet fittings caused by flow of the liquid past theinlet openings substantially retards flow from the manifold into therespective conduits until initial flow into the manifold accumulatessufficient liquid in the manifold to cause a substantial drop in thevelocity of fiow through the manifold;

each of said conduits having a plurality of spaced peripheral dischargepassages of alength substantially greater than its cross dimension fordirectional effect on the show therethrough, and being directed contraryto said given direction at an acute angle to the axis of the conduit;and

thermal responsive means to control said means to supply the liquid tothe conduits.

2. A combination as set forth in claim 1 which includes means on theexterior of the manifold to indicate the directions in which saidopenings of the fittings face for guidance in the installation of thefittings in the manifold as well as for guidance in the installation ofthe manifold with respect to the direction of flow through the manifold.

References Cited UNITED STATES PATENTS LLOYD L. IQING, Primary ExaminerR. W. T HIEME, Assistant Examiner US. Cl. X.R.

